Method of fabricating and assembling railroad brake shoes



Feb. 22, 1966 G. H. ARRASMITH METHOD OF FABRICATING AND ASSEMBLINGRAILROAD BRAKE SHOES 2 Sheets-Sheet 1 Original Filed Oct. 18, 1962INVENTOR GRANT H. ARRA$NHTH Feb. 22, 1966 G- H. ARRASMITH METHOD OFFABRICATING AND ASSEMBLING RAILROAD BRAKE SHOES Original Filed Oct. 18,1962 2 Sheets-Sheet 2 INVENTOR. gRANT H. ARRASMITH HE E.

United States Patent 3,235,952 METHOD OF FABRICATING AND ASSEMBLINGRAILROAD BRAKE SHOES Grant H. Arrasmith, Pearl River, N.Y., assignor toAmerican Brake Shoe Company, New York, NY, a corporation of DelawareContinuation of application Ser. No. 231,470, Oct. 18, 1962. Thisapplication Sept. 22, 1964, Ser. No. 398,244 3 Claims. (Cl. 29-407) Thisinvention relates to a method of making a new and improved brakeassembly for use in railroad braking system which utilizes compositiontype brake shoes instead of standard cast metal brake shoes, and isparticularly concerned with a brake assembly which prevents substitutionof standard cast metal shoes in the system.

This application is a continuation of application Serial No. 231,470,filed October 18, 1962, now abandoned.

The brake shoe which has long been standard in the railroad industrycomprises a cast metal body of substantial thickness, having a curvedbraking surface corresponding, in general, to the curvature of arailroad car or locomotive wheel. The dimensions and configurations ofthese cast metal shoes have long been standarized in the railroadindustry. The brake shoe includes a pair of end stops located atopposite ends of the convex back of the shoe and a pair of toe guidesextending from the end stops toward the center portion of the shoe. Anattaching lug is positioned in the center portion of the brake shoeback. The brake shoe is supported upon a brake head which includes anattaching lug recess into which the center attaching lug of the brakeshoe is fitted. A portion of the brake head engages the convex surfaceof the brake shoe, and the extremities or toes of the brake head form apair of recesses which receive the brake shoe toe guides.

It has been proposed that composition brake shoes be substituted forcast metal shoes in at least some railroad applications. Thesecomposition shoes, which inelude a composition brake body and a metalback or support structure, provide a substantially higher retardingforce per unit applied load than the standard cast metal shoes in thepresent state of the art, except under static or load speed conditions.In general, at higher speeds, it may be stated that cast metal shoes arehigh-pressure lowfriction devices, whereas composition shoes arehighfriction, low-pressure devices. Accordingly, it is usually desirableto incorporate substantially smaller brake cylinders in a system adaptedfor use with composition shoes, due to the lower shoe pressurerequirements. Substitution of cast metal brake shoes in a systemconstructed for use with composition shoes, therefore, may lead toinadequate braking and consequent danger to the railroad equipment,passengers, freight, and other property. Substitution of compositionshoes in a brake system constructed for use with cast metal shoes, onthe other hand, can cause substantial damage by excessively rapidbraking.

It is an object of the invention, therefore, to prevent substitution ofcast metal brake shoes in a railroad braking system adapted for use ofcomposition brake shoes by resort to a particular brake assembly whichwill accept the composition shoe and refuse the standard cast metalshoe.

A further object of the invention is a method of making a new andimproved brake head essentially that is similar to the long proven andreliable brake heads now in use on railroad equipment, but which willaccept only a specific type of brake shoe structure different from thestandard shoe structure. It is an important object of the invention toprovide a new and improved selective brake head, adapted for use withcomposition brake shoes but 3,235,952 Patented Feb. 22, 1966 not capableof accepting cast metal shoes, which may be conveniently andeconomically fabricated by modification of only one minor element of astandard brake head. An additional object of the invention is to providea new and improved brake assembly specifically adapted for use ofcomposition type brake shoes which is economical and convenient tomanufacture and can be fabricated with the same molds used for standardbrake heads with only insignificant changes.

Accordingly, the invention is directed to a method of making a selectivebrake assembly for preventing substitution of standard cast metal brakeshoes in a railroad braking system adapted for use of composition typebrake shoes and in which cast metal shoes may produce inadequatebraking. The brake assembly comprises a brake shoe including a metalsupport member of substantially arcuate configuration and a brake shoebody of molded composition material supported upon the concave surfaceof that support member. A brake shoe attaching lug is affixed to thesupport member and extends above the central portion of the convexsurface thereof; end stops are provided at the ends of the shoe. A toeguide is fabricated on one end of the metal support member and extendsabove the convex surface thereof. Unlike standard construction, the toeguide is not joined to the end stop of the shoe. Rather, the toe guideis spaced from the end stop to define a brake head tie bar receptacle.The brake assembly further includes a brake head having a recess forreceiving the brake shoe attaching lug and a face plate for engaging theconvex surface of the brake shoe support member. A tie bar is afiixed toone end of the brake head; this tie bar is adapted to engage in thereceptacle formed between the toe guide and end stop of the brake shoebut is positioned to interfere with the toe guide on a standard castmetal brake shoe, thereby preventing mounting of a cast metal shoe inthe brake head.

Other and further objects of the present invention will be apparent fromthe following description and claims and are illustrated in theaccompanying drawings which, by way of illustration, show a preferredembodiment of the present invention and the principle thereof and whatwe consider now to be the best mode in which we have contemplatedapplying that principle. Other embodiments of the invention embodyingthe same or equivalent principle may be used and structural changes maybe made as desired by those skilled in the art without departing fromthe present invention and the purview of the appended claims.

In the drawings:

FIG. 1 is an elevation view, partly in section, of a composition typebrake shoe constructed in accordance with the inventive concept;

lflG. 2 is a plan view of the brake shoe of FIG. 1;

FIG. 3 is an elevation view of a brake head constructed in accordancewith the inventive concept and shows a portion of the brake shoe of FIG.1 as supported on the brake head; and

FIG. 4 is a bottom view of the brake head of FIG. 3.

The composition brake shoe 20 illustrated in FIG. 1 comprises a metalsupport member 21 upon which is supported a composition brake shoe body22. Support member 21 is preferably formed from either hot-rolled orcold-rolled steel, hot-rolled steel usually being preferred. Compositionbody 22 may be cast or molded from any composition material suitable forrailroad braking service, depending upon the type car or locomotive towhich the brake shoe is to be applied. One suitable compositionmaterial, which exhibits superior characteristics with respect to heatand shock resistance and which affords a favorable ratio of wet to drycoefiicients of friction, is described and claimed in Patent No.2,901,456 of R. E. Spokes et al., issued August 25, 1959, and assignedto the same assignee as the present invention. This compositioncomprises a comminuted friction material, selected from the sillimanitegroup and related aluminum silicates, distributed in a heat-stablerubber binder; additional friction material in the form of cast ironparticles may also be included.

Composition body 22 may be provided with two or more slots 23 in thebraking surface thereof. The composition body is effectively bondedbetween a pair of longitudinal flanges 24 and 25 formed as an integralpart of support member 21. In addition, the composition body and supportmember may be interlocked with each other by means of a plurality ofindividual metal projections 27 formed integrally with and extendingfrom the lower or concave surface 26 of support member 21 intocomposition body 22. These individual metal anchor elements may beconveniently formed by a plurality of countersunk punched sections 27 insupport member 21. In addition, the brake shoe may be provided with aseparate metal reinforcing member (not shown) in accordance with theconstruction disclosed in Patent No. 2,885,- 037 of Rosser L. Wilson.

A center attaching lug 29 is clenched or otherwise affixed to supportmember 21 and extends above the central portion of the convex surfacethereof; as indicated in FIG. 2, attaching lug 29 is provided with akeyway 30 which is utilized in mounting the brake shoe upon a brakehead.

A pair of end stops 38 and 39 are formed at the opposite ends of brakeshoe 20. Preferably, the end stops are afforded by bending the endportions of support member 21 upwardly, laterally and downwardly toafiord reinforcement throughout the exposed surfaces of the end stops.In addition, at the end of the brake shoe adjacent end stop 38, aportion of support member 21 is punched out and bent upwardly to afforda toe guide member 31. At the opposite end of the brake shoe, a similarportion of the metal back is bent upwardly to afford a second toe guide32.

Unlike standard cast metal brake shoe construction, toe guide 31 is notcontiguous to and is not joined to the end stop 38 at the same end ofthe brake shoe. Instead, the toe guide is spaced from end stop 38 by asubstantial distance to 'afiord a brake head tie bar receptacle 33 whichis essential to the invention, as will be explained in detailhereinafter in connection with FIGS. 3 and 4. Similarly, toe guide 32 isspaced from the adjacent end stop 39, affording a second brake head tiebar receptacle 36 which is preferably essentially similar in dimensionsto the receptacle 33. It is important that the toe guide members 31 and32 be disposed in interfering alignment with the tie bar at the end of aconventional brake head used for cast metal shoes so that the toe guides31 and 32 effectively prevent mounting of brake shoe 20 upon a standardbrake head. In this manner, brake shoe 20 is protected againstincorporation in a braking system adapted for use with cast metal brakeshoes.

In FIG. 3, the brake shoe 20 of FIGS. 1 and 2 is shown mounted on abrake head 40. In most respects, brake head 40 is essentially similar tothe standard brake head construction employed for cast metal shoes andshown in AAR Standard drawing E-86A-1950; consequently, its individualelements are not described in detail except as they relate themodifications effected in accordance with the inventive concept. Brakehead 40 has a recess 41, which receives brake shoe attaching lug 29 inthe usual manner. The brake head further includes a face plate 42 whichengages convex surface 37 of the brake shoe support member. As in theconventional brake head and brake shoe assembly, the extremities 43 and44 of the brake head 40 engage the end sto R and 39, respectively, ofthe brake shoe to prevent longitudinal movement of the brake shoe withrespect to the brake head when the brakes are applied.

As thus far described, brake head 40 is entirely con= ventional and, inaccordance with one feature of the inventive concept, preferably has thesame basic dimen= sions and configuration as a standard brake head employed in conjunction with conventional cast metal brake shoes.

Brake head 40, however, further includes a pair of tie bars 53 and 54located at the opposite ends 43 and 44, respectively, of the brake head.A standard brake head would also include tie bars near the ends of thehead, as shown in the aforementioned AAR drawing. Tie bars 53 and 54,however, are located much closer to the end surfaces 55 and 56 of brakehead 40 than would be the case with a standard brake head construction.In fact, tie bars 53 and 54 must be located near enough to the ends 43and 44 of the brake head to interfere with the conventional toe guideson a cast metal shoe. Thus, it is these elements on the brake head thatprevent the mounting of a cast metal shoe thereon.

Further, tie bar 53 must be located in position to be received withinthe receptacle 33 afforded between toe guide 31 and end stop 38 on brakeshoe 20, as clearly shown in FIG. 3. The inner surface of the tie barfaces toe guide 31 and the outer surface faces end stop 38. Thus, tiebar 53 affords a firm guiding and mounting engagement with the endportion of brake shoe 20 in a manner essentially similar to thatafforded in a conven-' tional brake head. A corresponding mounting ofthe brake shoe on the brake head is achieved at the opposite end of theshoe by means of the second tie bar 54.-

As in a conventional brake assembly, brake head 40 is locked to brakeshoe 20 by means of a key (not shown) which engages a keyway 46 in thebrake head structure and which passes through the corresponding keyway30 in the center attaching lug 29 of brake shoe 20. Thus, the mountingarrangement for brake shoe 20 on brake head 40 is essentially similar tothat used conventionally, retaining all of the advantages of the provenand reliable standard construction, yet at the same time preventinginterchange of composition and cast iron shoes.

Fabrication of brake shoe 20 in accordance with the method of thepresent invention does not add in any way to the cost of the shoes.Thus, the punching operation required to form toe guides 31 and 32 is nomore complex or expensive than would be necessary to afford conventional.toe guides on the brake shoes. Except for the change in the toe guideconstruction, the basic construction of the composition shoe remainsunchanged. Of course, the toe guides are not restricted to the preciseconstruction illustrated. For example, the toe guides could be ofblock-like configuration and could comprise separate elements welded orotherwise secured to the metal back.

Brake head 40, on the other hand, can be cast in the same molds as areused for standard brake heads intended for cast metal braking systems,except for the change in location of tie bars 53 and 54 as compared withstandard tie bars. Indeed, brake head 40 can be fabricated by taking astandard brake head and cutting away the tie bar at each end. The tiebar can then be positioned outwardly of its normal location, in theposition shown in FIGS. 3 and 4, and welded in place. This relativelysimple and economical operation affords a complete brake head 40 meetingthe requirements of the present invention.

Hence, while preferred embodiments of the invention have been describedand illustrated, it is to be understood that they are capable ofvariation and modifica tion.

I claim:

1. In the manufacture of components for a specialized railroad brakingsystem comprising a plurality of cornposition-type brake shoes that cancause excessive wear and damage when incorporated in a standard systemconstructed for utilization of standard cast metal brake shoes, in whichspecialized braking system cast metal shoes provide inadequate braking,the method of fabricating component parts for said specialized system toprevent substitution of standard cast metal shoes therein and to preventincorporation of said composition-type shoes in a standard systemcomprising: afiixing a center mounting lug to each of thecomposition-type shoes intended for use in said specialized brakingsystem, said center mounting lug substantially corresponding to thecenter lug on a standard cast metal shoe, forming end stops at each endof each of the composition-type shoes, said end stops each extendingacross the end of the shoe and projecting above the back of the shoe,forming an upwardly extending toe guide near each end of each of thecompositiontype shoes, forming a pair of brake head tie bar receptacle-seach extending above the back of the shoe and in parallel relation tothe end stop at the corresponding end of the shoe and between the endstops and the toe guides, said toe guides being positioned forinterfering engagement with the tie bar of a standard brake head for acast metal shoe, whereby the composition type shoes cannot be mounted ona standard brake head, forming a center lug receptacle in each of thebrake heads for said specialized braking system, said center lugreceptacle substantially corresponding to the receptacle in a standardbrake head, transferring a pair of the bars from the location of the toeof a standard brake head for cast metal shoes to outward positions forthe composition shoes and affixing said tie bars at the outerextremities of each of the brake heads in position to interfere with thelongitudinally extending toe guides on a standard cast metal shoe andprevent mounting of a cast metal shoe on the brake head.

2. In the manufacture of components for a specialized railroad brakingsystem comprising a plurality of composition-type brake shoes that cancause excessive wear and damage when incorporated in a standard systemconstructed for utilization of standard cast metal brake shoes, in whichspecialized braking system cast metal shoes provide inadequate braking,the method of fabricating component parts for said specialized system toprevent substitution of standard cast metal shoes therein and to preventincorporation of said composition-type shoes in a standard systemcomprising: affixing a center mounting lug to each of thecomposition-type shoes intended for use in said specialized brakingsystem, said center mounting lug substantially corresponding to thecenter lug on a standard cast metal shoe, forming an upwardly extendingtoe guide near each end of each of the composition-type shoes, affordinga pair of brake head tie bar receptacles each extending above the backof the shoe and in parallel relation to said toe guide at thecorresponding end of the shoe and between an end of the shoe and a toeguide respectively, said toe guides being positioned for interferingengagement with the tie bars of a standard brake head for a cast metalshoe, whereby the composition-type shoes cannot be mounted on a standardbrake head, forming a center lug receptacle in each of the brake headsfor said specialized braking system, said center lug receptaclesubstantially corresponding to the receptacle in a standard brake head,transferring a pair of tie bars from the location of the toe of astandard brake head for cast metal shoes to outward positions for thecomposition shoes and aflixing said tie bars at the outer extremities ofeach of the brake heads in position to interfere with the longitudinallyextending toe guides on a standard cast metal shoe and prevent mountingof a cast metal shoe on the brake head.

3. The method of claim 2 wherein said toe guides are formed by bendingupwardly a portion of a metal support on the back of the shoe.

References Cited by the Examiner UNITED STATES PATENTS 2,900,711 8/1959Wilson 29407 2,902,752 9/1959 Keating et al. 29407 2,974,759 3/1961 Tacket al 188-243 3,088,557 5/1963 Cabble et al. 188243 WHITMORE A. WILTZ,Primary Examiner.

1. IN THE MANUFACTURE OF COMPONENTS FOR A SPECIALIZED RAILROAD BRAKINGSYSTEM COMPRISING A PLURALITY OF COMPOSITION-TYPE BRAKE SHOES THAT CANCAUSE EXCESSIVE WEAR AND DAMAGE WHEN INCORPORATED IN A STANDARD SYSTEMCONSTRUCTED FOR UTILIZATION OF STANDARD CAST METAL BRAKE SHOES, IN WHICHSPECIALIZED BRAKING SYSTEM CAST METAL SHOES PROVIDE INADEQUATE BRAKING,THE METHOD OF FABRICATING COMPONENT PARTS FOR SAID SPECIALIZED SYSTEM TOPREVENT SUBSTITUTION OF STANDARD CAST METAL SHOES THEREIN AND TO PREVENTINCORPORATION OF SAID COMPOSITION-TYPE SHOES IN A STANDARD SYSTEMCOMPRISING: AFFIXING A CENTER MOUNTING LUG TO EACH OF THECOMPOSITION-TYPE SHOES INTENDED FOR USE IN SAID SPECIALIZED BRAKINGSYSTEM, SAID CENTER MOUNTING LUG SUBSTANTIALLY CORRESPONDING TO THECENTER LUG ON A STANDARD CAST METAL SHOE, FORMING END STOPS AT EACH ENDOF EACH OF THE COMPOSITION-TYPE SHOES, SAID END STOPS EACH EXTENDINGACROSS THE END OF THE SHOE AND PROJECTING ABOVE THE BACK OF THE SHOE,FORMING AN UPWARDLY EXTENDING TOE GUIDE NEAR EACH END OF EACH OF THECOMPOSITIONTYPE SHOES, FORMING PAIR OF BRAKE HEAD TIE BAR RECEPTACLESEACH EXTENDING ABOVE THE BACK OF THE SHOE AND IN